Remove transparency from semitransparent pixel

Question

When drawn with the black brush with 50% of transparency, this color (when picked by color picker) recognized as gray color (128,128,128 rgb).

How to remove transparency to get black color?

What I managed for now is:

1. Duplicate layer until there's no transparency and then pick color
2. (theoretically): export to gif format, then open this gif and pick color with removed transparency

Is there more convenient method to find brushed transparent color value without transparency?

I'm using photoshop7

Here's some illustration-demonstration

_{(source: adelavida.com)}

Answer 1

Any level's transparency can be edited by transforming the layer transparency into a layer mask:

Layer > Layer Mask > From Transparency

So if we use image from @joojaa's answer:

This is what we get:

If you want to remove the transparency, you can just right click the mask and choose Delete Layer Mask. You can also disable the mask, use any tools to edit it etc.

Answer 2

Photoshop GUI is a bit unproductive for this problem. The data is there, its just extremely hidden*. The straight color can be read though its just a bit convoluted. If you need this often for whatever purpose record following action (I need this pretty often for 3D work):

1. Preparation Hide layers you don't want flatten for straight color.

   --Start recording--

2. Choose Image -> Calculations

   1. Set Both Modes to merged
   2. Both channels to red
   3. Result new channel
3. Repeat step 2 for green
4. Repeat step 2 for blue
5. make new layer, fill it with any solid color
6. Copy the created channels over to Red, Green and Blue channels.

You now have a layer without alpha.

Image 1: This is what I have as a starting point. Note: The png has alpha.

Image 2: Alpha channel removed, note i had some slightly colored pixels in there (I wondered why it trimmed that way). Note Photoshop defaults to white. You can also clearly see the dithering Photoshop makes.

This soould work in every PS version I have ever used.

PS: If you save the alpha separately and export a unmultiplied image.

* Presumably they dont want you to work on this level of processing. As if the world would collapse if transparent pixels did have color.

Answer 3

Update some time later.

I found a method separate the RGB values from the transparency to use it as a mask. Take a look at this answer: Is there an "inverse eraser" tool on Photoshop?

---

Don't flatten the image, don't reduce the colors exporting to gif.

Actually, it is a more interesting question that I originally thought.

I made some tests. Yes, it measures 127 on all channels. I thought it was gray but when I saw the levels on that layer it is actually black.

I think there is no way to change the opacity to 200%.

The workaround is to duplicate this layer several times and combine them. The first time the value were 63 and decreasing. When I have 7 duplicates (including the original the values is 1 and on the 8th duplicate its finally 0.

So an answer is (for this case) duplicate it 7 more times and combine the layers again. The number of combined layers depends on the maximum transparency you have and you need.

Keeping this method will allow you to preserve smooth borders and additional transparencies, for example, some internal transparency.

Answer 4

Unless the pixel you are looking at is on its own layer, it is impossible to tell whether the colour was applied as a low-opacity "pure" colour or a full-opacity mixed colour. In your example, a pixel that was the result of using 50% opacity black on a white background is identical to a pixel that resulted from applying 50% grey (or, rather, (128,128,128)) at 100% opacity. If the pixel is on a separate layer and you turn off all other layers that contribute to that pixel's value, the colour picker will reflect the colour actually used.

Answer 5

Getting the RGB value of a pixel should be easy, but it isn't because Photoshop premultiplies the alpha as layer transparency, and does not let you access the RGB channels without the transparency applied. I can think of a few techniques to get there, an easy one is to use Flaming Pear's Solidify-B plugin (free).

For clarity, Solidify-B attempts to fill the empty areas of a transparent layer with a pattern that makes sense visually. It is often used to expand opaque areas beyond their original boundaries so that you don't get black and white artefacts when rendering 3D elements. It's a happy accident that the plugins gives you the exact RGB value for semi-transparent pixels.

Answer 6

If you need eaxctly what you get when exporting to gif, then just flatten image. Layer->Flatten Image.

If you want to make 100% black from your gray brush stroke on new layer: 1. Select layer with brush stroke 2. Go Select -> Color Range... 3. Click with color sampler on your brush stroke and adjust selection level with Fuzziness slider. Click Ok. 4. Make new layer. 5. Go to Edit -> Fill... -> Select from Contents dropdown Color and select black color. Click Ok.